Prostate cancer is the most common malignancy among men in developed countries with current annual mortality of more than 27,000 in the United States and 570 in Ireland. Current practice in prostate cancer detection and staging leads to inaccurate assessments often resulting in many unnecessary treatments that impact negatively patient quality of life. This proposal comprises a US-Ireland R&D Partnership grant application from the Univ. of CT, University College Dublin (UCD) Medical School, National University of Ireland at Galway, and University of Ulster. The long term goal is to provide multi-biomarker diagnostics to enable accurate grading and staging of prostate cancer. Our hypothesis is that detection of a small panel of cancer biomarker proteins in patient serum can be used to accurately detect and establish stage and grade of prostate cancers. We will develop an optimized, validated biomarker panel and appropriate measurement devices to establish grade and stage of prostate cancer as well as to identify cancer-free patients. The biomarker panel will be optimized by evaluating a protein set combining general accepted biomarkers for prostate cancer with newly identified biomarker proteins for aggressive cancer identified by research from UCD and others. Development of assays and validation of the biomarker panel will be done with a rapid, ultrasensitive, versatile, microfluidic immunoassay already developed at Univ. of CT. Simultaneously, a simplified, low cost, disposable, label-free device for clinical use will be designed and fabricated by University of Ulster, and tested by the entire team. Validation will be done on samples obtained by UCD School of Medicine and George Washington University Hospital from prostate cancer patients and controls. Excellent patient follow-up from related ongoing studies in these institutions will facilitate additional informationfor validation of the panel in later years. Specific aims in brief include: (1) Develop immunoassays using an existing microfluidic array for an initial panel of proteins; (2) Investigate redox polyme mediation to simplify assay protocols and enhance sensitivity; (3) Validate analytical accuracy of array for initial protein panel by comparing to commercial bead based assays for a limited set of serum samples; (4) Analyze >600 serum samples from patient cohorts (Irish and USA) to establish disease prediction and staging characteristics using statistical analyses; use these data to optimize panel composition. (5) Design and fabricate a pump-free, label-free microfluidic array suitable for clinical measurements of the validated protein panel in a single drop of whole blood. This research strategy is specifically designed to translate to the clinic for prostate cancr diagnostics and personalized therapy.